Honorary Degree Speech, Curtin Uni

Transcription

1 Honorary Degree Speech, Curtin Uni Malcolm McCulloch Research School of Earth Sciences, Australian National University, Canberra, ACT. I would like to thank Curtin University of Technology for this award of an Honorary Doctorate. It certainly is humbling, and a great honour and privilege. I was among the first cohort of undergraduate and graduate students in the Department of Applied Physics, here at Curtin University, or as it was known in my day, the Western Australian Institute of Technology. I was especially fortunate in having John delaeter and Kevin Rosman as my supervisors and mentors. John was the founding head of the Department of Applied Physics, always busy with teaching and administrative roles, but despite this, played a pivotal, and I should say inspirational role, in leading a world-class research program in cosmochemistry. The educational experience that Curtin provided was first-rate, and equipped me with the necessary tools and skills to continue my life-long passion for learning and research. My Curtin experience gave me a thorough grounding in the fundamental sciences, of maths, chemistry, and of course physics. Armed with a Masters degree in Physics, and now being totally hooked on research and science generally, John delaeter again played a pivotal role in my career, as it was his reputation that opened the doors for me to enter the hallowed halls of the California Institute of Technology. From my PhD research at Caltech, then subsequent appointment at the Research School of Earth Sciences at ANU, my research expanded into the 1

2 terrestrial sciences, using isotope geochemistry to understand Earth processes. Over the past decade my research focus has moved to understanding the effects of climate change and impacts of land-use on coral reefs. The same skills in isotope geochemistry acquired whilst in John delaeter s lab, remain the essential tools to undertake this research. As we are all aware, climate change is now at the forefront of both scientific and public concern. Only last week, the Intergovernmental Panel on Climate Change released its 4 th report. The IPCC panel, comprising over 800 scientists from 130 countries, concluded the following: Warming of the climate system is unequivocal, as is now evident from observations of increases in global air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level and: Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations They also concluded that in the next 100 years global temperatures will very likely increase by 2-4 o C. The last time our planet underwent such a dramatic climate shift was following the end of the last ice age, which occurred between 10,000 to 20,000 years ago. During this period, massive ice sheets retreated from the northern continents with global temperatures increasing by about 4 C. This warming resulted from relatively subtle changes in the Earth s orbital parameters, causing the amount of solar radiation received by the northern Hemisphere to increase by a few percent. This amount of warming is about 2

3 the same as that predicted by 2100 from greenhouse gas emissions. Our era of global warming, however, is now occurring almost 100 times faster than the warming period that ended the last ice age. Our current rate of global warming is thus extremely rapid and of enormous concern. In fact, such rates of warming have rarely, if ever, been encountered by our planet. It s not my intention to be alarmist, but it should also be remembered that the Earth is a highly non-linear system, and so the possibility of relatively rare but catastrophic events should not be ignored. For example, in the IPCC report, the projected sea level rise of about 0.4m by 2100 is very likely, which is based on the well-known physics of thermal expansion of the oceans. But it is also likely that much larger increases of at least 6 meters may occur if ice sheets, such as those in Greenland and the west Antarctic, melt. The IPCC report has also generated newspaper headlines such as: Reef facing extinction The Great Barrier Reef will become "functionally extinct" within decades at the current rate of global warming. The Great Barrier Reef is the world s largest and most diverse coral reef system and is truly one of the World s greatest natural wonders. It is also a highly valuable natural resource that generates over 5 billion dollars annually from tourism alone. But why are coral reefs so susceptible to global warming? For reasons that we don t yet understand corals are extremely vulnerable. When reef waters exceed a critical temperature threshold by more than a few degrees for several days, the corals bleach and die as their algal symbionts, which provide energy to the corals, are expelled. We know from the fossil coral record that on timescales of 1000 s of years, corals can adapt to warmer 3

4 conditions. However, there is yet no evidence that corals can adapt on short timescales of years or decades to avoid the effects of bleaching caused by global warming. So in the coming decades, there is a significant threat that some coral species will no longer exist as they will be subject to almost continual bleaching. So what can be done to prevent this? Actions taken now can substantially ameliorate some of the worst effects. Clearly the reduction of CO 2 emissions is a key challenge, which requires more efficient energy usage, and the development of new and alternative technologies, such as solar and wind power, as well as the wise use of our vast natural endowments of gas, coal, and uranium. Although these challenges are great, this new era of climate change also provides many new opportunities for our scientific community, and you as young graduands, can play a large part in resolving these problems within the coming decades. Given the expertise and calibre of Australia s scientific community, and thus our potential technological capacity, there is clearly a great opportunity before us to play a leading role in the development and implementation of a new energy regime, which takes advantage of our natural resources. But even under the best scenarios and assuming that the political obstacles can be overcome, reducing greenhouse emissions by itself is not enough. At this stage all we can do is try to ameliorate the now inevitable effects of climate change. For sensitive ecosystems, such as coral reefs, which have a major role in maintaining the balance within a complex biosphere, we must improve their ability to withstand the stresses induced by climate change. That is, we must increase their resilience. This involves the reduction of local anthropogenic pressures such as overfishing, with the establishment of no-take zones as has been partially implemented in the 4

5 GBR and Ningaloo Reef. In addition to this, it is also important to reduce the amount of land-based pollution entering reef systems. River run-off from degraded catchments, carry high levels of nutrients that favours the growth of macro-algae at the expense of corals. Disconnecting river systems from agricultural and grazing activities is especially critical. It is thus important that we act now, not only at a national level, but also locally, if coral reefs and other sensitive ecosystems are to have a future in our world. In such critical times, scientists have a clear responsibility, not only in getting the science right, with the caveat of recognising the limitations of both our knowledge and understanding of the science of complex systems, but also in educating the general populous (which includes politicians), about how our planet works and how we impact it, now and in the future. We therefore have a unique role in effecting attitudes and appropriate policies to ensure a sustainable environment and future for our planet. Finally I would like to thank you all for this wonderful opportunity and to congratulate all the Graduates for your outstanding achievements. 5